Outsourced workers at the University of London are campaigning to be brought in-house, holding a strike on Thursday to support their demands.

Cleaners, security guards, porters and other workers want to be employed directly by the university, which they hope will give them greater security, improved benefits and the ability to better negotiate with their employers.

While they are essential to the running of the university, many of them are currently supplied to the institution by an external facilities company.

Work is frequently outsourced under the guise of cutting costs, and workers say they receive fewer benefits in areas like sick pay, holiday pay and pensions as those employed directly.

Magdalena Chytra, who protested outside the university's senate house om Thursday, said she has been employed by three companies in her seven years as a cleaner at the university, while security officer Omar Toryalae says he’s been employed by five facilities firms during his 10 years on the job.

"We feel like we're being sold from company to company," he told Sky News.

"We want to work directly for the University of London, to be part of the University of London and have the rights that come with that."

Both say they've struggled to address concerns with the university because of working through a middle company, and that conditions have become worse as contracts change hands to difference outsourcing companies.

Jason Moyer-Lee, the General Secretary of Independent Workers Union of Great Britain, said outsourcing contracts often hit more vulnerable workers, such as migrants and those in jobs that are often precarious or low-paid, the hardest.

"The public is becoming aware now more than ever of the massive waste, incompetence and unfair treatment of workers inherent in the outsourcing model, and the University of London is no exception," he said.

A spokesperson for the University of London told Sky News that it had begun a review of the performance of contracted out facilities management services, and that it would be discussing pay, conditions, benefits and development opportunities with the contractors employing outsourced workers.

"In common with many institutions in the sector, the University of London has a number of contracted out services," they said.

"We are aware of an ongoing industrial dispute within one of our contracted-out services. It would not appropriate for the University to comment on the employment arrangements of another organisation."